Clamp



E. SAMPSON CLAMP Filed Nov. 24, 1939 June 3, 1941.

Patented June 3, 1941 UNITED STATES LPATENT OFFICE CLAMP Eli Sampson, Marshfield, Oreg. Application November 24, 1939, Serial No. 305,908

l1 Claim.

My invention relates to bar clamps, commonly used in wood-working shops, which may be extended to twice their unextend'ed length.

At present, wood-Working shops must have on hand not only a great number of clamps, but a' great variety of lengths, to meet the varied demands of their customers. An object of my invention is to cut down the number of clamps usually required.

Clamps are also needed on the job and it becomes necessary for journeymen to carry clamps, sometimes very long ones, from the shop to the job, and from job to job. Long clamps are very inconvenient to carry about. Another object of my invention is to provide a clamp, that may be readily carried about in the average hand box, whose range of usefulness may be doubled.

The accompanying sheet of drawings discloses one design of my invention. Fig. 1, is a side view of the clamp partiallyextended; Fig. 2, is a top View of Fig. l; Fig. 3, is an isometric view of the T-shaped' head or dog on the intermediate or ex tension bar; Fig. 4, is a section on- 4-4 of Fig. 1; Fig. 5, is a section on 5-5 of Fig. 1; Fig. 6, is an end view of the do-g on the tail work-engaging xture; and Fig. 7, is a p-artial end View of the clamp with the tail fixture dog removed.

Throughout the drawing and this specification similar numerals refer to similar parts.

In the design which I have used' to illustrate my invention, the clamp A comprises two sections, the long side bar assembly B and' the short side Ibar assembly C. Normally the bars of both sections are in longitudinal alignment, as shown by the solid lines in Fig. l. When the length of the clamp is being altered, assembly C is iirst tilted as shown by its dot and dash outline 3 of Fig. 1, whereby the two assemblies are dis-engaged and assembly C may be shifted longitudinally with respect to assembly B to shorten or lengthen the clamp A.

'Ihe assembly B includes two long rectangular side bars 4 and 5 held together in spaced' apart relation by an inverted T-shaped spreader 6 whose leg portion 'I is interposed between the head end' of said bars and secured to them, in the instant case, by welding, the method which I have employed to fixedly join parts of my clamp. 'Ihe head portion 8 of the spreader 6 depends beneath the side bars 4 and 5 with each of its shoulders 9 in intimate contact with the face I of the bar above, the outer face I l of said head' portion being ush with the outer face I 2 of said bars. The head portion 8 serves as an abutment for the head work-engaging iixture I3 which is provided with an aperture I4 for the reception of the side bars 4 and 5 uponwhich said fixture is a sliding t. A portion i5 of the xture I3 depends beneath the side bars and terminates in a widened Work-engaging portion I5. The portion I5 is provided with a bearing aperture I7 for the reception of the turned down end I8 of the screw I9 which is threaded into and thru the head portion 8. The other end of said screw I9 extending outside and rearwardly of the Vhead portion 8 terminates in a crank arm 2B disposed at right angles thereto. This crank arm 20 is provided with a handle 2| extending at right angles thereto whereby the movement of the screw I9 may be manually controlled by the clamp user in moving the xture I3 longitudinally forward or back on the side bars 4 and 5. The end I8 of the screw I9 is provided with an annular groove 22 into which extends the turned down end 23 of, the screw 24 threaded into the portion I5 of the lixture I3 whereby said Iixture is caused to move in accordance with the screw movement.

The opposite end of the side bars 4 and 5 are held' together in spaced apart relation by the top tie plate 25 secured in the dap 25 formed in the upper face 21 of and at the end of said bars. The lower tie plate 28 is secured in the dap 29 formed in the lower face I 0 of the bars rearwardly of the upper dap. This arrangement provides upper and' lower conning and supporting means for the short bar assembly C and permits said assembly to 4be tilted as shown and above described. By setting the tie plates in the daps the outer faces may be flush with the outer faces of the bars thereby eliminating obstructions to the free movement of fixtures over said bars.

The short side bar assembly C includes an elongated rectangular intermediate or extension bar 30 to the sides 3| of which, at one of its ends, is secured two short bars 4a andv 5a similar in cross section to the long bars 4 and 5. The intermediate bar may have the same thickness as the side bars or it may be proportioned to provide the same strength as the both long side Abars 4 and 5 combined. However, its width and thickness must be such as to permit it to be slid'able thru and between the tie pilates and side bars of assembly B.

A wedge-shaped T-head or dog 32 is fixedly secured at the opposite end of the intermediate bar 30 with the top face 33 of said head ush with the top face 21 of the side bars 4 and 5, and 4a and 5a, which have notches cut in their top face 21 similar to and to receive said wedgeshaped T-head. The notch 34a is cut adjacent the head fixture I3 when the same abuts the head portion 8 of the spreader 6. The notch 34h is cut adjacent the top tie plate 25, While the notches 34 are equally spaced between the notches 34a and 3411. The short side bars 4a and 5a are provided with at least one notch 34C. This notch 34e is engageable only by the dog 35 on the tail work-engaging fixture 36, while the notches 34, 34a, and 34h, are only engageable by the T-shaped head or dog 32, whereby the intermediate bar 36 is held in any desired working relation to the side bars 4 and 5. When the end 31 of the short side bars abuts the end 38 of the long side bars, the proportion and arrangement of parts is such that the T-head or dog 32 is in engagement with the notch 34a. By tilting assembly C as shown in Fig. 1, the same may be moved longitudinally outward to engage any of the notches 34 or the notch 34h, in which latter instance the distance between the work-engaging fixture i3 and 36 is doubled. The tail Workengaging xture 36 may be moved longitudinally over the side bars of either assembly and its dog 35 may engage any of the notches of the clamp. It is to be noted and remarked that the two `assemblies are not separable when once the T-shaped head is fixed to the intermediate bar 30. The head must be secured to the bar after the same has been passed thru the tie plates and is between the side bars.

The tail work-engaging fixture 36 is provided with an aperture 39 for the reception of the side bars 4 and 5 or 4a and 5a upon which said fixture is a sliding fit. The fixture 36 has a portion 40 which depends below the side bars and which terminates in a widened work-engaging portion 4I whose work-engaging face 42 is adjacent to the work-engaging face 43 on head fixture I3. The fixture 36 also has a portion 44 which extends above the side bars and has its leading upper corner bifurcated to form a pair of ears 45 spaced apart for the reception of a dog 4S hinged on a pin 41 press fitted in said ears. In forming said ears thus, a wedge-shaped tie member 48 is left to ride upon the side bars and form a support for the fixture. The lower portion 49 of the dog 46 is formed to fit and for engagement of any of the notches in the clamp, and is readily lifted out of said engagement by depressing the upper end 5D. To prevent the accidental removal of the fixture 36 from assembly C, the stop pins 5| are provided in the side bars 4a and 5a. Since the notches are formed in the side bars, and the intermediate bar is positioned between them, the dog 46 is notched as shown in Fig. 6, to straddle said intermediate bar since it extends into the notches.

The basic idea of my invention has been incorporated in a design which has been minutely shown and described and which in practice works perfectly. However, the design admits of changes in form and arrangement without departing from the basic idea and therefor I do not limit my invention to the design shown and described but extend it to all that comes fairly within the scope of the appended claims.

I claim:

In a clamp, the combination of a pair of long rectangular side bars; a pair of similar short side bars; a plurality of notches formed in the upper face of the bars, at least one of which is in the short bars; means to hold the long side bars together in spaced apart relation including a top tie plate at one end of said bars and a bottom tie plate spaced rearwardly of the top tie plate; an intermediate rectangular bar having one of its ends secured between the short side bars and its opposite end provided with transverse ears which together with the bar end form a T-shaped head, said ears being shaped to engage a notch in the long side bars', said intermediate bar being slidable longitudinally between said tie plates and said long side bars and normally parallel to said side bars and tilted thereto when the head is being moved from one notch to another; a work-engaging head fixture slidable longitudinally on the long side bars; means to control its movement; a work-,engaging tail xture slidable longitudinally on both the long and short side bars and having a dog to engage a notch on either of said bars, the top and bottom edges of the bars between the head and tail xturcs being free of work-inarring projections.

ELI SAMPSON. 

